In an imaging device, an auto focus (AF) technique for automatically achieving a focused state is generally classified into a contrast detection method and a phase difference detection method. The phase difference detection method is capable of a high-speed AF operation, which is superior to the contrast detection method.
As the phase difference detection method, a pupil-division phase difference detection method is generally known. The pupil-division phase difference method is a method in which a phase difference detection pixel or a focus detection pixel (hereinafter, generally referred to as a “phase difference detection pixel) in addition to imaging pixels are arranged in the same light receiving region (imaging region) to measure an AF distance in an imaging area, that is to obtain a phase difference detection signal indicating a shift direction and a shift amount of a focus.
In a case where the phase difference detection pixel is arranged in the imaging region of the solid-state imaging device, it is necessary to enhance the detection sensitivity of the phase difference detection pixel while maintaining a high sensitivity characteristic of the imaging pixels. Thus, in the related art, in a light blocking film formed to have an opening corresponding to each pixel, the opening corresponding to the phase difference detection pixel is formed to have a size smaller than that of the opening corresponding to the imaging pixel. Further, the focus of a microlens corresponding to the phase difference detection pixel is set to be “front defocusing” (refer to PTL1). Here, the “front defocusing” refers to a state where the focus is shifted in front of a subject.